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Yan A, Chen Y, Li N, Ma T, Qi Y, Xu D. Dewatering performance of aerobic granular sludge under centrifugal with different sludge conditioning agent. Front Microbiol 2024; 15:1386557. [PMID: 38952447 PMCID: PMC11215069 DOI: 10.3389/fmicb.2024.1386557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/29/2024] [Indexed: 07/03/2024] Open
Abstract
The aerobic granular sludge(AGS) technology draw scientific researchers attention, and more and more scientific research focuses on it, due to its superior advantages, such as good settling performance, high biological phase, high toxicity resistance and multiple biological effects. With the rapid development of AGS technology, a considerable amount of residual AGS will be produced, and dehydration is the biggest bottleneck of sludge reduction. This study investigated the dewatering process and method of residual AGS cultured by continuous flow experiment. Experiments were conducted using centrifugal dewatering technology with a dosing scheme to analyze the granular sludge dewatering process, and investigate the release process of EPS component in AGS dewatering. Our results implied the specific resistance of AGS has a very low value ((1.82 ± 0.03) × 109 m/kg) and it was not obvious for the conditioning effect of chemical conditioner on AGS dewatering. However, the moisture content can be reduced to 63.5% after dewatering with the presence of inorganic substances. The addition of drinking water treatment plant sludge (Alum sludge) can improve the efficiency of the dewatering of AGS. A possible dewatering process of AGS dewatering was proposed which was divided into two stages: First, a considerable amount of free water in the sludge was quickly removed under the action of gravity without pressure filtration. Second, the bound water release required cooperation between applying centrifugal or pressing force to grind granular cells and separate protein-like substances with the inorganic matter inside the granular sludge. The possible mechanism of AGS dewatering and hypothesis dewatering process are useful to optimize the AGS dewatering process.
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Affiliation(s)
- Ailan Yan
- Nanxun Innovation Institute, Zhejiang University of Water Resources and Electric Power, Hangzhou, China
- College of Water Conservancy and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, China
| | - Yongfei Chen
- Hangzhou Yongzhan Environment Technology Co., Ltd., Hangzhou, China
| | - Ningyu Li
- College of Water Conservancy and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, China
| | - Ting Ma
- China Railway Eryuan Engineering Group East China Exploration & Design Co., Ltd., Hangzhou, China
| | - Yiting Qi
- College of Water Conservancy and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, China
| | - Dong Xu
- College of Water Conservancy and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, China
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Liu Z, Luo F, He L, Wang S, Wu Y, Chen Z. Physical conditioning methods for sludge deep dewatering: A critical review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 360:121207. [PMID: 38788408 DOI: 10.1016/j.jenvman.2024.121207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/17/2024] [Accepted: 05/18/2024] [Indexed: 05/26/2024]
Abstract
Sludge is an inevitable waste product of sewage treatment with a high water content and large volume, it poses a significant threat of secondary pollution to both water and the atmosphere without proper disposal. In this regard, dewatering has emerged as an attractive method in sludge treatment, as it can reduce the sludge volume, enhance its transportability and calorific value, and even decrease the production of landfill leachate. In recent years, physical conditioning methods including non-chemical conditioners or energy input alone, have been extensively researched for their potential to enhance sludge dewatering efficiency, such as thermal treatment, freeze-thaw, microwave, ultrasonic, skeleton builders addition, and electro-dewatering, as well as combined methods. The main objective of this paper is to comprehensively evaluate the dewatering capacity of various physical conditioning methods, and identify key factors affecting sludge dewatering efficiency. In addition, future research anticipated directions and outlooks are proposed. This work is expected to provide valuable insights for developing efficient, eco-friendly, and low-energy consumption techniques for deep sludge dewatering.
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Affiliation(s)
- Zhuo Liu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Fang Luo
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Lingzhi He
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Siqi Wang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yi Wu
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhuqi Chen
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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3
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Wan C, Huang S, Li M, Zhang L, Yuan Y, Zhao X, Wu C. Towards zero excess sludge discharge with built-in ozonation for wastewater biological treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171798. [PMID: 38521252 DOI: 10.1016/j.scitotenv.2024.171798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 02/25/2024] [Accepted: 03/16/2024] [Indexed: 03/25/2024]
Abstract
In this study, a biological treatment process, which used a built-in ozonation bypass to achieve sludge reduction, was built to treat the industrial antifreeze production wastewater (mainly composed of ethylene glycol). The results indicated there is a positive correlation between ozone dosage and sludge reduction. At the laboratory level, the MLSS in the system can be stably controlled at around 3400 mg MLSS L-1 under the dosage of 0.18 g O3 g-1 MLSS. Ozonation can increase the compactness of sludge flocs (fractal dimension increased from 1.89 to 1.92). Ozone destroys microbial cell membranes and alters the structure of sludge flocs through direct oxidation through electrophilic reactions. It leads to the release of intracellular polysaccharides, proteins, and other biological macromolecules in microorganisms, thereby promoting the implicit growth of microbial populations. Some bacteria such as g_Pseudomonas, g_Gemmobacter, etc. have strong ethylene glycol degradation ability and tolerance to ozonation. The removal of ethylene glycol includes the glyoxylate cycle, glycine serine carbon cycle, and the glutamate-cysteine ligase pathway of assimilation. Gene KatG and gpx may be key factors in improving microbial tolerance to ozonation. The comprehensive evaluation from the perspectives of cost and carbon emission shows that choosing ozone cracking-implicit growth in wastewater treatment systems has significant cost advantages and application value.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
| | - Shiyun Huang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Min Li
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Lei Zhang
- School of Civil & Environmental Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Yue Yuan
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiaomeng Zhao
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Changyong Wu
- Research Center of Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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Zhou B, Zhao G, Yan C, Dong Y, Wang D, Liang J, Zhang M, Zhang D, Zhou Y, Li J, Zhou L. Aeration pre-treatment role in improving the performance of bio-conditioning dewatering of food waste anaerobic digestate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 177:298-306. [PMID: 38368642 DOI: 10.1016/j.wasman.2024.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 02/20/2024]
Abstract
Bio-conditioning dewatering followed by activated sludge process (BDAS) is a promising technology for purifying food waste anaerobic digestate (FWAD). However, the bio-conditioning dewatering efficiency is often affected by FWAD properties and ambient temperature. Here, we firstly reported that aeration pre-treatment of FWAD played an important role in improving the bio-conditioning dewatering performance of FWAD. The study found that the accumulated carbonate (CO32-) in FWAD severely affected the flocculation of Fe-containing flocculant formed in microbial fermentation liquor due to the competitive consumption of the flocculant by CO32-. The capillary suction time (CST) and specific resistance to filtration (SRF) of the bio-conditioned FWAD increased from initial 77.8 s and 2.0 × 1012 m/kg to 122.7 s and 3.4 × 1012 m/kg, respectively, within 1 day of aeration. Prolonged aeration pre-treatment of FWAD could reduce its CO32- concentration and total alkalinity. Additionally, the aeration pre-treatment simultaneously decreased the proportion of macromolecular organic matter that hindered dewatering and the content of total solids (TS) and hydrophilic protein-like substances in FWAD. After 20 days of aeration followed by bio-conditioning, the CST and SRF reduced to final 36.5 s and 2.3 × 1011 m/kg, respectively, indicating a substantial improvement in dewatering performance. Successive forced aeration combined with the addition of CaCl2 to eliminate adverse factors mainly CO32- was a feasible and cost-effective strategy to realize bio-conditioning dewatering of FWAD in less than 2 days and a lower reagents dose of bio-conditioning, which was helpful in the engineering application of the novel BDAS process for FWAD purification.
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Affiliation(s)
- Bo Zhou
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Guangliang Zhao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Cheng Yan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Dong
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Dianzhan Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianru Liang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China
| | - Mingjiang Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Dejin Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yujun Zhou
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jiansheng Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Lixiang Zhou
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China.
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Yang Y, Yang X, Chen Y, Li X, Yang Q, Li Y, Ma P, Zhang H, Xu S. Response surface optimization of sludge dewatering process: synergistic enhancement by ultrasonic, chitosan and sludge-based biochar. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2024; 89:1630-1646. [PMID: 38619894 DOI: 10.2166/wst.2024.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 02/20/2024] [Indexed: 04/17/2024]
Abstract
Due to the colloidal stability, the high compressibility and the high hydration of extracellular polymeric substances (EPS), it is difficult to efficiently dehydrate sludge. In order to enhance sludge dewatering, the process of ultrasonic (US) cracking, chitosan (CTS) re-flocculation and sludge-based biochar (SBB) skeleton adsorption of water-holding substances to regulate sludge dewaterability was proposed. Based on the response surface method, the prediction model of the specific resistance to filtration (SRF) and sludge cake moisture content (MC) was established. The US cracking time and the dosage of CTS and SBB were optimized. The results showed that the optimal parameters of the three were 5.08 s, 10.1 mg/g dry solids (DS) and 0.477 g/g DS, respectively. Meantime, the SRF and MC were 5.4125 × 1011 m/kg and 76.8123%, which significantly improved the sludge dewaterability. According to the variance analysis, it is found that the fitting degree of SRF and MC model is good, which also confirms that there is significant interaction and synergy between US, CTS and SBB, and the contribution of CTS and SBB is greater. Moreover, the process significantly improves the sludge's calorific value and makes its combustion more durable.
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Affiliation(s)
- Yahong Yang
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; Wenzhou Engineering Institute of Pump & Value, Lanzhou University of Technology, Wenzhou, Zhejiang 325105, China E-mail:
| | - Xingfeng Yang
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; School of Environmental and Chemical Engineering, Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai University, Shanghai 200444, China
| | - Yirong Chen
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; Wenzhou Engineering Institute of Pump & Value, Lanzhou University of Technology, Wenzhou, Zhejiang 325105, China
| | - Xiaowei Li
- School of Environmental and Chemical Engineering, Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai University, Shanghai 200444, China
| | - Qiyong Yang
- College of Resources & Environment, Jiujiang University, Jiujiang, Jiangxi 332005, China
| | - Yangying Li
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; Wenzhou Engineering Institute of Pump & Value, Lanzhou University of Technology, Wenzhou, Zhejiang 325105, China
| | - Pengjing Ma
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; Wenzhou Engineering Institute of Pump & Value, Lanzhou University of Technology, Wenzhou, Zhejiang 325105, China
| | - Huining Zhang
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China
| | - Shenghui Xu
- School of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China
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Zhou B, Wang D, Yan C, Zhao G, Liu X, Zhang D, Liang J, Zhou Y, Li J, Zhou L. A novel approach for purifying food waste anaerobic digestate through bio-conditioning dewatering followed by activated sludge process: A case study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123644. [PMID: 38402935 DOI: 10.1016/j.envpol.2024.123644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/16/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Although anaerobic digestion is the mainstream technology for treating food waste (FW), the high pollutant concentration in the resultant food waste anaerobic digestate (FWAD) often poses challenges for the subsequent biochemical treatment such as activated sludge process. In this study, taking a typical FW treatment plant as an example, we analyzed the reasons behind the difficulties in treating FWAD and tested a novel process called as bio-conditioning dewatering followed by activated sludge process (BDAS) to purify FWAD. Results showed that high concentrations of suspended solids (SS) (16439 ± 475 mg/L), chemical oxygen demand (COD) (24642 ± 1301 mg/L), and ammonium nitrogen (NH4+-N) (2641 ± 52 mg/L) were main factors affecting the purification efficiency of FWAD by the conventional activated sludge process. By implementing bio-conditioning dewatering for solid-liquid separation, near 100% of SS and total phosphorus (TP), 90% of COD, 38% of total nitrogen (TN), and 37% of NH4+-N in the digestate could be effectively removed or recovered, consequently generating the transparent filtrate with relatively low pollution load and dry sludge cake (<60% of moisture content). Furthermore, after ammonia stripping and biochemical treatment, the effluent met the relevant discharge standards regulated by China, with the concentrations of COD, TN, NH4+-N, and TP ranging from 151 to 405, 10-56, 0.9-31, and 0.4-0.8 mg/L, respectively. This proposed BDAS approach exhibited stable performance and low operating costs, offering a promising solution to purify FWAD in practical engineering and simultaneously realize resource recovery.
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Affiliation(s)
- Bo Zhou
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Dianzhan Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Cheng Yan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guangliang Zhao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xuan Liu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Dejin Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jianru Liang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yujun Zhou
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Jiansheng Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Lixiang Zhou
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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Yuan H, Zhu N. Progress of improving waste activated sludge dewaterability: Influence factors, conditioning technologies and implications and perspectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168605. [PMID: 37989393 DOI: 10.1016/j.scitotenv.2023.168605] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/06/2023] [Accepted: 11/14/2023] [Indexed: 11/23/2023]
Abstract
Large amounts of waste activated sludge (WAS) as a by-product generated from the biological treatment in wastewater treatment plants (WWTPs) is of high moisture content (MC), organic pollutants, heavy metals and pathogenic bacteria, it may cause serious environmental ecological risk without appropriate disposal. More than one half of the total operation cost is accounted for sludge disposal in a WWTP. Dewatering is an essential and important step during the sludge treatment and disposal process for it could efficiently reduce its volume, and be beneficial to the subsequent treatment and disposal of sludge. However, sludge should be conditioned before mechanical dewatering because of its high hydrophilicity. In this work, it presented a comprehensive review on sludge dewatering including summarizing the dewaterability measurement indexes, affecting factors, conditioning technologies, the improvement mechanisms. Finally, based on the eventual disposal and low carbon emission target, the implications and perspectives development of sludge conditioning were discussed. Based on the above discussion, there is no unified theoretical insight of the improvement mechanism of sludge dewaterability. In addition, the relationship between the microstructure of organic matters in sludge floc and the dewaterability should be deepened. Especially, how to choose the optimal conditioning technology for sludge dewatering lies in the physical and chemical properties of sludge, however, the carbon emission of the conditioning and dewatering process also needs to be considered. Accordingly, green, low-cost and organic conditioning agents are the direction of future research, and the establishment of automatic operating system and real-time evaluation index system is the key challenge.
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Affiliation(s)
- Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China.
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Li H, Li C, Zhou K, Ye W, Lu Y, Chai X, Dai X, Wu B. Intelligent upgrade of waste-activated sludge dewatering process based on artificial neural network model: Core influential factor identification and non-experimental prediction of sludge dewatering performance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 346:118968. [PMID: 37714087 DOI: 10.1016/j.jenvman.2023.118968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/24/2023] [Accepted: 09/09/2023] [Indexed: 09/17/2023]
Abstract
Owing to the extremely complex compositions and origins of waste-activated sludge (WAS), the multiple physiochemical properties of WAS have impacts on its dewaterability, and there is a complex interaction relationship among the multiple physiochemical properties, which makes it difficult to identify the controlling factors on WAS dewaterability. Accordingly, there is still no unified certainty in the appropriate ranges of physiochemical properties for the optimal dewaterability of sludge from different sources, resulting in a lack of clear theoretical basis for technical selection and optimization of sludge dewatering processes. The large consumption of conditioning chemicals and low process efficiency stand for the major deficiency of existing sludge conditioning technologies. This study proposed to use a non-linear, adaptive and self-organizing artificial neural network (ANN) model to integrate the multiple physiochemical properties of WAS affecting its dewaterability, and WAS dewatering performance under certain conditioning schemes could be predicated by ANN model with the multiple physiochemical properties and conditioning operation parameters as the input arguments. Thus, the laborious filtration experiments for screening conditioning chemicals could be replaced by the input adjustment of ANN model. Rooted mean squared error (RMSE) of 6.51 and coefficient of determination (R2) of 0.73 confirmed the satisfied stability and accuracy of established ANN model. Furthermore, the predictor-exclusive method revealed that the exclusion of polar interface free energy decreased most, which reflected the importance of surface hydrophilicity reduction in sludge dewaterability improvement. All the contributions presented here were believed to provide an intelligent insight to improve the experience operation status of WAS dewatering process.
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Affiliation(s)
- Hewei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Chunjiang Li
- Shanghai Technology Innovation Center of Sludge Treatment and Resourcification, Shanghai CEO Environmental Protection Technology Co., Ltd., 1668 Guoquan Road, Shanghai, 200438, China
| | - Kun Zhou
- Shanghai Municipal Engineering Design Institute (Group) Co., Ltd., 901 Zhongshan North 2nd Road, Shanghai, 200092, China
| | - Wei Ye
- College of Electronic and Information Engineering, Tongji University, 4800 Cao'an Highway, Shanghai, 201804, China
| | - Yufei Lu
- Shanghai Technology Innovation Center of Sludge Treatment and Resourcification, Shanghai CEO Environmental Protection Technology Co., Ltd., 1668 Guoquan Road, Shanghai, 200438, China
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Boran Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
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9
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Nabwey HA, Tony MA. Dewatered Sludge Decorated with Nanoparticles for Alum Sludge Conditioning towards the Concept of "End-of-Waste". NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2903. [PMID: 37947747 PMCID: PMC10647506 DOI: 10.3390/nano13212903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
The circular economy concept is leading environmental engineering in the search for "End-of-Waste" criteria. Untreated waste residue results from drinking water treatment plants, causing severe environmental issues, and its reuse is essential. In this regard, this investigation introduces the beneficial reuses of alum sludge cake to close the loop between sludge waste generation and reuse. Considering alum sludge as a resource for dewatering instead of its categorization as a waste reflects an "End-of-Waste" approach. Alum sludge cake was thermally calcined at 400 °C and named thermally treated alum sludge cake (TAS-cake). In this study, TAS-cake decorated with magnetite with a percent weight of 5 to 1%, respectively, was labeled as TAS-cake@Fe-(5-1). X-ray diffraction (XRD) and morphologies were applied to characterize the hybrid composite. A Fenton-based hybrid composite was applied to extrude water from alum sludge for 7 min of conditioning time. Furthermore, the factorial design based on response surface methodology (RSM) was applied to optimize the operational variables. TAS-cake@Fe-(5-1) and hydrogen peroxide revealed 1.2 g/L and 740 mg/L doses at pH 3.0, showing pronounced performance and revealing the highest capillary suction time (CST) reduction, which reached 53%. A temperature increase also showed a pronounced enhancement effect on the sludge dewaterability that reached 72% when 55 °C was applied. Thus, such a novel conditioner is a promising candidate for alum sludge conditioning.
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Affiliation(s)
- Hossam A. Nabwey
- Department of Mathematics, College of Science and Humanities in Al-Kharj, Prince Sattam bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
- Basic Engineering Science Department, Faculty of Engineering, Menoufia University, Shebin El-Kom 32511, Egypt;
| | - Maha A. Tony
- Basic Engineering Science Department, Faculty of Engineering, Menoufia University, Shebin El-Kom 32511, Egypt;
- Advanced Materials/Solar Energy and Environmental Sustainability (AMSEES) Laboratory, Faculty of Engineering, Menoufia University, Shebin El-Kom 32511, Egypt
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10
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Wang J, Xu S, Zhao K, Song G, Zhao S, Liu R. Risk control of antibiotics, antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) during sewage sludge treatment and disposal: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162772. [PMID: 36933744 DOI: 10.1016/j.scitotenv.2023.162772] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/14/2023] [Accepted: 03/06/2023] [Indexed: 05/06/2023]
Abstract
Sewage sludge is an important reservoir of antibiotics, antibiotic resistance genes (ARGs), and antibiotic resistant bacteria (ARB) in wastewater treatment plants (WWTPs), and the reclamation of sewage sludge potentially threats human health and environmental safety. Sludge treatment and disposal are expected to control these risks, and this review summarizes the fate and controlling efficiency of antibiotics, ARGs, and ARB in sludge involved in different processes, i.e., disintegration, anaerobic digestion, aerobic composting, drying, pyrolysis, constructed wetland, and land application. Additionally, the analysis and characterization methods of antibiotics, ARGs, and ARB in complicate sludge are reviewed, and the quantitative risk assessment approaches involved in land application are comprehensively discussed. This review benefits process optimization of sludge treatment and disposal, with regard to environmental risks control of antibiotics, ARGs, and ARB in sludge. Furthermore, current research limitations and gaps, e.g., the antibiotic resistance risk assessment in sludge-amended soil, are proposed to advance the future studies.
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Affiliation(s)
- Jiaqi Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Yangze Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Siqi Xu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Kai Zhao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ge Song
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shunan Zhao
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Ruiping Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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11
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Liang J, Zhou Y. Iron-based advanced oxidation processes for enhancing sludge dewaterability: State of the art, challenges, and sludge reuse. WATER RESEARCH 2022; 218:118499. [PMID: 35537253 DOI: 10.1016/j.watres.2022.118499] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
The increasing amount of sewage sludge produced in wastewater treatment plants (WWTPs) poses a great challenge to both environment and economy globally. As a requisite process during sludge treatment, sludge dewatering can significantly minimize the sludge volume and lower the operational cost for downstream transportation and disposal. Iron-based advanced oxidation process (AOP), a robust and cost-effective technique with relatively low technical barriers for high-level sludge dewatering, has been widely explored in the past 20 years. The development was mainly driven by the demands of efficient and sustainable sludge conditioning technology and the flexible sludge management approaches. The application of iron-based AOPs in sludge dewatering process attracts more and more attention. In this work, we discussed the current application of iron-based AOPs technology in the sludge dewatering processes in a holistic manner, summarized the factors affecting the sludge dewaterability in the treatment processes, and analyzed the mechanisms of iron-based AOPs to improve dewatering processes. Furthermore, we elaborated potential advantages, limitations, and challenges associated with implementing iron-based AOPs in the full-scale plants and shared the opportunities for sludge reutilization. This review aims to contribute to the development of highly efficient iron-based AOPs for sludge dewatering and offer perspectives and directions towards the new-generation of WWTPs with the sustainable and eco-friendly benefits.
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Affiliation(s)
- Jialin Liang
- Engineering and Technology Research Center for Agricultural Land Pollution Integrated Prevention and Control of Guangdong Higher Education Institute, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore.
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12
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Wen Q, Liu B, Chen Z. Simultaneous recovery of vivianite and produce short-chain fatty acids from waste activated sludge using potassium ferrate as pre-oxidation treatment. ENVIRONMENTAL RESEARCH 2022; 208:112661. [PMID: 35032543 DOI: 10.1016/j.envres.2021.112661] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/12/2021] [Accepted: 12/30/2021] [Indexed: 05/16/2023]
Abstract
Recovery resources from waste active sludge (WAS) is an effective way to alleviate the predicament of WAS disposal, and it is also conducive to the carbon neutralization of wastewater treatment systems. This study discussed the strategy of WAS anaerobic fermentation after pre-oxidation with potassium ferrate (K2FeO4, PF), which can simultaneously recover vivianite and enhance SCFAs production. The results showed that PF pre-oxidation considerably shortened the fermentation time of SCFAs to 2 days, and the main Fe-P mineral was vivianite. The optimal PF dosage of 0.06 g Fe (VI)/g TSS for pre-oxidation WAS resulted in the maximum SCFAs production and vivianite recovery rate of 3698.2 ± 118.98 mg COD/g VSS and 32.39%, respectively. The mechanism analysis showed that the oxidizing properties of PF significantly accelerated the disintegration of tight EPS, release of protein and sludge acidification efficiency. Moreover, the PF strengthened the transfer of P to the solid phase, forming the Fe-P mineral and unsaturated coordination state of phosphate group. Then the key microorganism Geobacter reduced the Fe3+ in Fe-P state to Fe2+ and combined unsaturated phosphate to form vivianite. This study provides an alternative method for resource recovery and environmentally friendly disposal of WAS and contributes to the carbon neutrality of urban water systems.
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Affiliation(s)
- Qinxue Wen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Baozhen Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Zhiqiang Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China; School of Civil Engineering, Lanzhou University of Technology, Lanzhou, 730070, PR China.
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13
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Wu B, Wang H, Li W, Dai X, Chai X. Influential mechanism of water occurrence states of waste-activated sludge: Potential linkage between water-holding capacity and molecular compositions of EPS. WATER RESEARCH 2022; 213:118169. [PMID: 35180582 DOI: 10.1016/j.watres.2022.118169] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/22/2021] [Accepted: 02/07/2022] [Indexed: 05/06/2023]
Abstract
The water occurrence states in waste-activated sludge (WAS) are crucial to its dewaterability and significantly influenced by the water-retaining capacity of extracellular polymeric substances (EPS) matrix. Accordingly, the non-selective •OH-oxidation processes were widely reported for the sludge dewaterability improvement, just because it can non-selectively destruct complex structure units of EPS, no matter these structure units are crucial to EPS water-holding capacity or not. But these non-selective processes may also require the large consumption of oxidant chemicals, which limits their wide application. This study specifically focused on the •OH-induced variation in molecular compositions of EPS and the corresponding effects on water occurrence states of WAS, which is expected to lay a foundation for optimizing the efficiency of oxidation-based sludge conditioning. Especially, through a novel method based on the equilibrium dialysis with alkaline titration, the typical hydrophilic functional groups of EPS were quantitatively analyzed. The results indicated that the free amino group (-NH2) had the greater impact on the water-holding capacity of EPS than the acidic hydroxyl groups (-OH). Nevertheless, by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS), the hydrophilic heteroatom classes (e.g. N:Cw) were found to be less sensitive to the varying oxidant dosage than the molecular saturation degree (e.g. weighted averages of double bond equivalents (DBEw) and aromatic index (AImod,w)). •OH modified the nitrogen-containing or oxygen-containing functional groups, but could not completely remove these hydrophilic functional groups from EPS macromolecules. Therefore, the potential competition for •OH between the hydrophilic functional groups and the unsaturated structure units of EPS was clarified, which guides directions that developing highly-efficient sludge conditioning approaches should be based on the selective removal of hydrophilic functional groups instead of improving •OH production efficiency.
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Affiliation(s)
- Boran Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Hao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Wenxuan Li
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01 T-Lab Building, 117411, Singapore
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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14
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Luo HC, Guo WQ, Zhao Q, Wang HZ, Ren NQ. Compared effects of “solid-based” hydrogen peroxide pretreatment on disintegration and properties of waste activated sludge. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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Özyonar F, Korkmaz MU. Sequential use of the electrocoagulation-electrooxidation processes for domestic wastewater treatment. CHEMOSPHERE 2022; 290:133172. [PMID: 34914950 DOI: 10.1016/j.chemosphere.2021.133172] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/27/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
Nowadays, the decrease in useable water resources day by day necessitates studies on the protection of resources by treating wastewater. It is also one of the best options for reusing the water to be treated, and electrochemical technologies can be an alternative to existing technologies, because of the easy operation and effectiveness of pollutants treatment. The study evaluated the treatment of domestic wastewater by Electrocoagulation-Electrooxidation successive processes in continuous and batch modes. The effects of the operational parameters on the Electrocoagulation and Electrooxidation processes were determined for removals of chemical oxygen demand, ammonium-nitrogen, nitrate-nitrogen, turbidity, phosphate-phosphorus, nitrite-nitrogen, and Escherichia coli. The experiments revealed that the Electrocoagulation process effectively removed all pollutants but not ammonium-nitrogen. After the Electrocoagulation process was completed, ammonium-nitrogen from domestic wastewater treatment was removed with the Electrooxidation process for further treatment. The optimum operational conditions in the Electrocoagulation process were electrode type iron anode-carbon felt cathode, current density 100 A m-2, initial pH original, and operation time 20 min. Under these conditions, removal efficiencies of chemical oxygen demand, turbidity, phosphate-phosphorus, nitrate-nitrogen, nitrite-nitrogen, and Escherichia coli were found to be 90.2%, 96%, 88.2%, 73.6%, and 97.9%, respectively. The removal efficiencies for the optimum operating conditions of the Electrooxidation process using Ti/SbO2 anode and stainless steel cathode were obtained as 95.4% (chemical oxygen demand), 89.4% (ammonium-nitrogen), and 99.99% (Escherichia coli) at 100 A m-2, 5 mm electrode distance, and 30 min operation time. Finally, the EC process is an effective process for removing chemical oxygen demand, phosphate-phosphorus, turbidity, nitrite-nitrogen, and nitrate-nitrogen. However, the Electrooxidation process is a successful process for the treatment of ammonium-nitrogen and Escherichia coli. This research revealed that the sequential processes effectively removed organic, inorganic, and Escherichia coli from domestic wastewater.
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Affiliation(s)
- Fuat Özyonar
- Department of Environmental Engineering, Sivas Cumhuriyet University, 58140, Sivas, Turkey.
| | - Mehmet Utku Korkmaz
- Department of Environmental Engineering, Sivas Cumhuriyet University, 58140, Sivas, Turkey.
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16
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Zhang W, Chen J, Tang M, Wu H, Liu M, Ai J, Wang D. Citric acid chelated Fe(II) catalyzed peroxidation for simultaneously improving sludge dewaterability and antibiotic resistance genes (ARGs) removal. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.119925] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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17
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Yin R, Peng J, Sun J, Li C, Xia D, Shang C. Simultaneous removal of hydrogen sulfide, phosphate and emerging organic contaminants, and improvement of sludge dewaterability by oxidant dosing in sulfide-iron-laden sludge. WATER RESEARCH 2021; 203:117557. [PMID: 34418644 DOI: 10.1016/j.watres.2021.117557] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Liquid sludge often contains odorous and toxic hydrogen sulfide and high levels of FeII compounds (e.g., iron sulfides), due to the extensive use of iron salts for hydrogen sulfide control in sewers and for enhanced primary treatment and phosphate removal in wastewater treatment plants. We proposed and verified that dosing appropriate chemical oxidants in the sulfide-iron-laden sludge can be a simple and cost-effective strategy to remove hydrogen sulfide, phosphate, and emerging organic contaminants, and to improve sludge dewaterability simultaneously. Among the seven oxidants investigated, H2O2, ClO2 and NaClO2 were the more cost-effective oxidants than others to control hydrogen sulfide release from the liquid sludge. Dosing these three oxidants also improved sludge dewaterability and removed dissolved phosphate from the liquid sludge, with H2O2 performing the best. Hydrogen sulfide was removed via both direct oxidation by the dosed oxidants and indirect oxidation by the FeIII that was in-situ formed from oxidation of the FeII compounds in the sludge. The in-situ formed FeIII also precipitated/adsorbed the soluble phosphate into the solid form (FePO4). Fenton-like reactions occurred between H2O2 and the FeII compounds in the sludge, and hydroxyl radicals (HO•) were generated. HO• oxidized hydrogen sulfide, destructed refractory organic emerging contaminants and sludge extracellular polymeric compounds (EPSs), and improved the sludge dewaterability. The formation of HO• can be enhanced by hydrogen sulfide and the sludge EPSs present in the sludge through providing more available FeII for the Fenton-like reactions. This study demonstrates the importance of selecting and dosing suitable oxidants to the sulfide-iron-laden sludge with due consideration for the multiple benefits in engineering practices. The same principles may be also used in formulating a dual oxidant-iron strategy to treat sulfide-iron-laden sewage, sludge, and sediments for simultaneous abatement of various pollutants.
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Affiliation(s)
- Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jiadong Peng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianliang Sun
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, School of Environment, South China Normal University, Guangzhou 510006, China.
| | - Chenchen Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Dehua Xia
- School of Environmental Science & Engineering, Sun Yat-sen University, Guangzhou, China
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
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18
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Li E, Wang Y, Zhang D, Fan X, Han Z, Yu F. Siderite/PMS conditioning-pressurized vertical electro-osmotic dewatering process for activated sludge volume reduction: Evolution of protein secondary structure and typical amino acid in EPS. WATER RESEARCH 2021; 201:117352. [PMID: 34157572 DOI: 10.1016/j.watres.2021.117352] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/20/2021] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
In this study, the siderite/PMS conditioning-pressurized vertical electro-osmotic dewatering (PEOD) process was used to reduce the volume of activated sludge (AS). The changes in water content, cell, extracellular polymeric substances (EPS) distribution, protein secondary structures and typical amino acids in EPS fractions of AS along siderite/PMS conditioning-PEOD process were investigated. Results showed that the final water content (WC) of dewatered AS was 58.02% under the RSM optimized conditioning conditions of 0.05 g/g TSS siderite dosage, 0.23 g/g TSS PMS dosage, 600 kPa mechanical pressure and 20 V voltage. At conditioning and PEOD stages, the bound water content(BWC) of AS decreased by 25.23% and 91.76%, respectively. The HO• and SO4-· generated from siderite activating PMS could lead to the disruption of cells. The ratio of Ala-to Lys (Ala/Lys) showed strong negative correlations with BWC or WC in slime (RBWC2=-0.803, p<0.01; RWC2=-0.771, p<0.01) and TB-EPS (RBWC2=-0.693, p<0.01; RWC2=-0.705, p<0.01), and could be considered as an indicator of AS dewaterability. Compared with raw AS, conditioning led to the occurrence of the denser protein structure in TB-EPS and the looser one in slime. The contact number between Ala-and water decreased in TB-EPS and increased in slime, which indicated that the migration of water adhered in TB-EPS to outer layer. At the DG, MC and EC process, while the looser protein structure in TB-EPS and the denser one in slime occurred, as well as higher contact number between Ala-and water in TB-EPS than that in slime, which indicated that more water flowed outsider of slime than TB-EPS. This implied that the variations of the compactness of protein secondary structures and the contact number between Ala-and water in EPS layers correlated with AS dewaterability.
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Affiliation(s)
- Enrui Li
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Yili Wang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China.
| | - Daxin Zhang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Xiaoyang Fan
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Zhibo Han
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Fuling Yu
- College of Science, Beijing Forestry University, Beijing 100083, China
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19
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Guo J, Gao Q, Chen Y, He Q, Zhou H, Liu J, Zou C, Chen W. Insight into sludge dewatering by advanced oxidation using persulfate as oxidant and Fe 2+ as activator: Performance, mechanism and extracellular polymers and heavy metals behaviors. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 288:112476. [PMID: 33827020 DOI: 10.1016/j.jenvman.2021.112476] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/14/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
This study established a Fe2+/persulfate oxidation system to dewater sludge in WWTPs. Dewatering performance, persulfate consumption and the variations of sludge pH, TN and TP during dewatering process were monitored. EPS and ζ-potential behaviors for ameliorating sludge dewatering was investigated. Transformation, leaching toxicity and environmental risk of heavy metals in sludge during dewatering were determined. Results demonstrated that after treated by Fe2+/persulfate oxidation system with 0.6 mmol/g-VS of persulfate at Fe2+/persulfate molar ratio 0.6, WC decreased to 53.5% and SCST increased to 4.15, which implied an excellent improvement of sludge dewatering. The fast persulfate consumption, the decrease of sludge pH and the increase of TN illustrated the positive effects of Fe2+ in activating persulfate and the decomposition of EPS by the activation products, SO4•- and •OH. Another product (Fe3+) generated during persulfate activation could decrease the content of phosphorus-containing matter (released from EPS decomposition) through the precipitation reaction with PO43-. The decrease of TOC and UV-254 happened in HPO-A, HPO-N and TPI-A organic substance of EPS (mainly contained in TB-EPS fraction) indicated that the destruction of hydrophobic organic matter of EPS would stimulate the release of bound water, which was beneficial to dewater sludge. The largest protein loss in TB-EPS (from 24.5 to 10.7 mg/L) indicated that the effective decomposition of TB-EPS could significantly ameliorate sludge dewatering. The increase of ζ-potential indicated the degradation of organic matter in EPS with negative charge. To sum up, the destruction of protein-like substances in hydrophobic organic matter of TB-EPS was the main mechanism for improving sludge dewatering by Fe2+/persulfate oxidation system. 3D-EEM fluorescence spectroscopy analysis proved that these protein-like substances were mainly tryptophan protein and humic acid. Moreover, due to the disruption of EPS, the contents of heavy metals in sludge, and their leaching toxicity and environmental risk were reduced. Therefore, Fe2+/persulfate oxidation system has potential and application prospects to improve sludge dewatering and optimize sludge management in WWTPs.
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Affiliation(s)
- Junyuan Guo
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China.
| | - Qifan Gao
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| | - Yihua Chen
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| | - Qianlan He
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| | - Hengbing Zhou
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| | - Jinbao Liu
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| | - Changwu Zou
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| | - Wenjing Chen
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
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20
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Xiao Y, Lu Y, Zheng G, Zhou L. Impact of initial sludge pH on enhancing the dewaterability of waste activated sludge by zero-valent iron-activated peroxydisulphate. ENVIRONMENTAL TECHNOLOGY 2021; 42:2573-2586. [PMID: 31869277 DOI: 10.1080/09593330.2019.1707880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/15/2019] [Indexed: 06/10/2023]
Abstract
In this study, the usefulness of the ZVI/S2O82- system in enhancing the dewaterability of waste activated sludge was studied at different initial sludge pH levels to reveal the associated mechanisms. Results showed that conditioning of sludge by the ZVI/S2O82- system at acidic initial sludge pHs enhanced sludge filterability and the dryness of dewatered sludge cake, while only the sludge filterability was improved at neutral initial sludge pH. In particular, the conditioning treatment using 0.353 g/g DS of ZVI and Na2S2O8 with a mole ratio of 1.25:1, at initial sludge pH 2.52, was the optimum condition to improve sludge dewaterability, which reduced the moisture content of dewatered sludge cake to only 69.8% and meanwhile reduced sludge CST and SRF to only 70.9% and 40.7% of that of raw sludge, respectively. During the conditioning treatment, sludge microbial cell lysis resulting from decreasing the initial sludge pH led to the reduction in the moisture content of dewatered sludge cake, while the oxidation of sludge EPS and the coagulation of the disrupted sludge flocs achieved by the ZVI/S2O82- system improved sludge filterability. A kaolin suspension experiment revealed that with a decrease in system pH, the oxidation effect was gradually inhibited and the coagulation effect offset the disruption effect on sludge flocs to improve the filterability of sludge. Therefore, the conditioning of waste activated sludge using the ZVI/Na2S2O8 system at acidic initial sludge pHs is useful to enhance the sludge filterability and the dryness of dewatered sludge cake, both of which are crucial for improving sludge dewatering performance.
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Affiliation(s)
- Yifan Xiao
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Yi Lu
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, People's Republic of China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, People's Republic of China
| | - Guanyu Zheng
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, People's Republic of China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, People's Republic of China
| | - Lixiang Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, People's Republic of China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, People's Republic of China
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21
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Li Y, Liu L, Zhang Q, Su Y, Zhou M. Hybrid electro-Fenton and peroxi-coagulation process for high removal of 2,4-dichlorophenoxiacetic acid with low iron sludge generation. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138304] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Effect of on-Site Sludge Reduction and Wastewater Treatment Based on Electrochemical-A/O Combined Process. WATER 2021. [DOI: 10.3390/w13070941] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Working on sludge with electrochemical oxidation is beneficial to promote the subsequent recessive growth of microorganisms in the sludge. To achieve the on-site sludge reduction, this study combined the anoxic/oxic (A/O) process with the electrochemical oxidation process based on the cell lysis-cryptic growth theory by determining the experimental conditions and mechanism of electrochemical cell lysis. The sludge reduction and effluent treatment of the combined process in practical operation were studied. The results showed that the cumulative sludge discharge had been reduced by 37.1% compared with that of the A/O process, and the apparent sludge yield had been reduced by 39.1% during the 30-day operation time, indicating that the electrochemical-A/O combined process could have a considerable sludge reduction effect. After the treatment, chemical oxygen demand (COD), ammonium nitrogen, and total nitrogen in the effluent of the combined process reached 33.02 mg/L, 0.83 mg/L, and 9.95 mg/L, respectively. Due to the limitation of the A/O process, the removal of total phosphorus was poor. As a result, poly aluminum chloride (PAC) was employed to achieve a chemical removal of phosphorus, by which the total phosphorus (TP) of the effluent was controlled to be lower than 0.5 mg/L.
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23
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Wang J, Meng X, Chen Y, Zheng G, Zhou L. Simultaneously attenuating antibiotic resistance genes and improving the dewaterability of sewage sludge by conditioning with Fenton's reagent: the pivotal role of sludge pre-acidification. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:13300-13311. [PMID: 33175353 DOI: 10.1007/s11356-020-11562-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
Fenton conditioning processes have been recently employed to improve the dewaterability of sewage sludge. However, it remains unclear whether the conditioning with Fenton's reagent would simultaneously attenuate antibiotic resistance genes (ARGs) in sludge and improve sludge dewaterability. It was found in the present study that sludge pre-acidification played a pivotal role in simultaneously removing ARGs and improving sludge dewaterability by conditioning with Fenton's reagent. When the sewage sludge was pre-acidified to pH = 3.0 and was then conditioned using Fenton's reagent, the absolute abundances of the total ARGs and the total mobile genic elements (MGEs) in conditioned sludge were reduced by 1.85-2.10 and 2.84-3.12 log units, respectively. Additionally, sludge capillary suction time (CST) and specific resistance to filtration (SRF) were drastically reduced, and the moisture content (MC) in dewatered sludge cake was reduced to only 60.61-69.95%. Such effective attenuation of ARGs and MGEs in conditioned sludge led to their removal in both the dewatered sludge cakes and dewatering filtrate. However, only the improvement of sludge dewaterability was attained by sludge conditioning with Fenton's reagent but without sludge pre-acidification. During the conditioning treatment, the removal of loosely bound extracellular polymeric substance (EPS) and tightly bound EPS in conditioned sludge contributed to the improvement of sludge dewaterability, and the damage of sludge microbial cells was highly correlated with the attenuation of antibiotic resistance. Thus, sludge pre-acidification combined with conditioning using Fenton's reagent can be employed to simultaneously attenuate the antibiotic resistance in sewage sludge and improve sludge dewaterability.
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Affiliation(s)
- Jiajun Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiaoqing Meng
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yu Chen
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guanyu Zheng
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China.
- Department of Environmental Engineering, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
| | - Lixiang Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, 210095, China
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Jessieleena AA, M P, Mp S. Comparative study of Fenton, Fe 2+/NaOCl and Fe 2+/(NH 4) 2S 2O 8 on tannery sludge dewaterability, degradability of organics and leachability of chromium. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123495. [PMID: 32739724 DOI: 10.1016/j.jhazmat.2020.123495] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/23/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
In this work, a comparative analysis of Fenton, Fe2+/NaOCl and Fe2+/(NH4)2S2O8 assisted advanced oxidation processes was carried out to study its efficacy in enhancing tannery chemical sludge dewaterability. Experimental results showed that, after conditioning of sludge at optimum pH, oxidant and catalyst dosage, capillary suction time (CST) was decreased by 75 ± 5 % and moisture content of sludge cake (M.Ccake) was reduced to 74 ± 2 % for all processes at 10 min reaction time. Among the three processes, Fe2+/(NH4)2S2O8 process was noted to have larger impact on the breakdown of sludge cells, which is reflected in terms of its highest amount of total organic carbon, protein and total dissolved solids present in the separated sludge fractions. In addition, Fe2+/(NH4)2S2O8 process was also observed to leach out largest fraction say 73.3 % of chromium present in the raw sludge into the treated sludge filtrate. The investigation carried out through zeta potential and scanning electron microscopy reveals the role of a two-step mechanism, namely oxidation followed by coagulation in enhancing the sludge dewaterability. Further studies on the possibility of utilizing dried treated sludge as biomass fuel could be carried out.
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Affiliation(s)
- A Angel Jessieleena
- Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
| | - Priyanka M
- Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
| | - Saravanakumar Mp
- Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
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25
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Gao S, Wang Y, Zhang D, Fan X, Guo Y, Li E, Zheng H. Insight to peroxone-Fe(III) joint conditioning-horizontal electro-dewatering process on water reduction in activated sludge: Performance and mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123441. [PMID: 32688188 DOI: 10.1016/j.jhazmat.2020.123441] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/11/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Peroxone disintegration-Fe(III) coagulation (peroxone-Fe(III)) joint conditioning was proposed to enhance the horizontal electro-dewatering (HED) effect of activated sludge (AS). Operating parameters were optimized and the evolutions of AS physicochemical properties, water fractions distribution, organic matter, extracellular polymeric substance (EPS) key components, functional groups, and protein secondary structures during the process were identified. Under the optimized joint conditioning parameters, dewatered AS achieved a final water content of 84.88 ± 0.17% and its bound water content (BWC) was decreased by 1.88 ± 0.28 g/g dry solid. During peroxone pretreatment, the yielded HO decreased the AS floc size, disintegrated the EPS network structure and cell wall, released the bound water, and extracted proteins, polysaccharides, and humic acid-like materials. Furthermore, soluble microbial byproduct-like materials (SMBP) in the EPS layers and tyrosine in tightly bound EPS significantly increased. Protein structures were destroyed, decreasing their water affinity. Subsequent Fe(III) addition re-coagulated broken flocs fragments and EPS fractions, built water flow channels, removed tyrosine and SMBP, and reduced α-helix percentage in slime, facilitating AS dewatering. After joint conditioning, the bound water and intracellular substances were further released by HED. Therefore, the peroxone-Fe(III)-HED process exhibited an excellent performance in AS water reduction.
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Affiliation(s)
- Shihui Gao
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing, 100083, China
| | - Yili Wang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing, 100083, China.
| | - Daxin Zhang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing, 100083, China
| | - Xiaoyang Fan
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing, 100083, China
| | - Yajie Guo
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing, 100083, China
| | - Enrui Li
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing, 100083, China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Regions Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, 400045, China
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Guo J, Jia X, Gao Q. Insight into the improvement of dewatering performance of waste activated sludge and the corresponding mechanism by biochar-activated persulfate oxidation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140912. [PMID: 32683170 DOI: 10.1016/j.scitotenv.2020.140912] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/22/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
A novel activator, corn biochar, was produced to activate persulfate to dewater waste activated sludge (WAS). Results demonstrated that the biochar-activated persulfate oxidation can effectively improve the dewatering performance of WAS. After treating WAS by biochar-activated persulfate oxidation (biochar dosage: 2.1 g/L, persulfate concentration: 7.5 mM) at the original WAS pH, standardized-capillary suction time (SCST) increased to 4.21 times and moisture content (MC) decreased to 43.4%, indicating an excellent performance of WAS dewatering. The decrease of residual persulfate with the increasing biochar dosage during WAS dewatering process illustrated that the role of persulfate in improving WAS dewatering was because of the biochar activation. The behaviors of extracellular polymers (EPS) proved that the protein in tightly bound EPS (TB-EPS) linked to WAS dewatering, and its content significantly reduced to 10.5 mg/g-volatile solids (VS) after WAS treatment. Three-dimensional fluorescence spectroscopy for EPS once again proved that the disintegration of tryptophan protein and humic acid (hydrophobic organic substances in EPS) was responsible for the improvement of WAS dewatering. To sum up, the biochar-activated persulfate oxidation was a feasible application in improving WAS dewatering.
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Affiliation(s)
- Junyuan Guo
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China.
| | - Xiaojuan Jia
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China
| | - Qifan Gao
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China
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Wang X, Wang W, Zhou B, Xu M, Wu Z, Liang J, Zhou L. Improving solid-liquid separation performance of anaerobic digestate from food waste by thermally activated persulfate oxidation. JOURNAL OF HAZARDOUS MATERIALS 2020; 398:122989. [PMID: 32768831 DOI: 10.1016/j.jhazmat.2020.122989] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/02/2020] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
Anaerobic digestion is a promising ecofriendly technology for the management of the continuous increasing food waste (FW). However, the large amount of resulting anaerobic digestate are very difficult to be purified due to high concentration of suspended colloids. Solid-liquid separation is a pivotal step for the subsequent biological treatment of the digestate by activated sludge process. The dewaterability of digestate could directly reflect the solid-liquid separation performance. In this study, a thermally-activated persulfate (PDS) conditioning method was utilized to enhance the digestate dewaterability. Results revealed that PDS thermally conditioning significantly improved the dewaterability by decreasing digestate pH and decomposing organic substances in digestate. The decline of pH, which was resulted from PDS thermally activation reaction, facilitated filterability improvement via reducing the surface negative charges and prompting the oxidizing ability of PDS-relevant radicals. Protein, the main organic component in digestate, was most closely correlated with digestate dewaterability. Fortunately, they were also the most vulnerable constituent under the oxidation attack. PDS thermal conditioning at 80°C was proven to be the most suitable for improving the solid-liquid separation performance of anaerobic. For practical application in conditioning the anaerobic digestate from FW, the conditions should be further optimized according to the digestate characteristic.
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Affiliation(s)
- Xiaomeng Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Wei Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Bo Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Min Xu
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Zhenjiang Wu
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Jianru Liang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Lixiang Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
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Zhou X, Jin W, Wang L, Ding W, Chen C, Xu X, Tu R, Han SF, Feng X, Lee DJ. Improving primary sludge dewaterability by oxidative conditioning process with ferrous ion-activated peroxymonosulfate. KOREAN J CHEM ENG 2020. [DOI: 10.1007/s11814-020-0517-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Wu B, Dai X, Chai X. Critical review on dewatering of sewage sludge: Influential mechanism, conditioning technologies and implications to sludge re-utilizations. WATER RESEARCH 2020; 180:115912. [PMID: 32422413 DOI: 10.1016/j.watres.2020.115912] [Citation(s) in RCA: 219] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 04/21/2020] [Accepted: 05/02/2020] [Indexed: 05/17/2023]
Abstract
Sewage sludge (mainly composed of excessive bio-sludge) is an inevitable by-product of biological wastewater treatment process and contains various toxic substances, such as pathogens, heavy metals, and organic contaminants. The production of sewage sludge may cause serious pollution risks without appropriate disposals. As the essential step of sludge treatment, dewatering plays significant roles in minimizing the sludge volume, facilitating the transportation, increasing the calorific value and even reducing the leachate production in landfill sites. This paper presents a comprehensive review on the issues related to dewatering of sewage sludge. Section 1 starts with the environmental implications of sludge dewatering. Section 2 deals with the concepts and challenges about differentiation of bound water fractions, and also reviews the recent progress of in-situ visualization of water occurrence states in bio-flocs. Section 3 discusses about how various physiochemical properties influence the sludge dewaterability, and the insufficiency in in-situ micro-characterization of sludge constituents is pointed out. Section 4 reviews the existing conditioning technologies for sludge dewaterability improvement, and the advantages/disadvantages of each technology in terms of applicable occasions, material consumption, energy consumption and environmental impacts are evaluated. The last section (section 5) specifically analyzes the feasibility of integrating sludge dewatering and re-utilization, and raises attention to the potential environmental risks of dewatering conditioning. Based on the above discussion, we propose that a unified theory for sludge dewaterability improvement remains to be established. Especially, how the molecular structures of sludge compositions affect the solid-water interface behavior requires to be deepened, which will further unravel the mechanism behind strong water-holding capacities of bio-flocs. Additionally, we believe that the key challenges for sludge dewatering is how to select the appropriate conditioning technique according to the physiochemical properties of target sludge. The reliable indicators for real-time control of conditioning operations are still deficient, e.g., dynamic dosage control of conditioning chemicals. Accordingly, the potential environmental risks of excessive conditioning chemicals should be taken into more consideration.
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Affiliation(s)
- Boran Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai, 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai, 200092, China
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai, 200092, China.
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30
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Wang HF, Hu H, Wang HJ, Bai YN, Shen XF, Zhang W, Zeng RJ. Comprehensive investigation of the relationship between organic content and waste activated sludge dewaterability. JOURNAL OF HAZARDOUS MATERIALS 2020; 394:122547. [PMID: 32289621 DOI: 10.1016/j.jhazmat.2020.122547] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/09/2020] [Accepted: 03/15/2020] [Indexed: 06/11/2023]
Abstract
The relationship between sludge organic fraction and its dewaterability is well known in practice. However, the formal study to reveal the underlying reason is limited. To improve understanding of the nature of organic content on sludge dewatering process, this study systematically evaluated the effects of sludge organic content on its dewaterability and revealed the underlying mechanism. Analysis of 10 waste activated sludge (WAS) samples with varying organic contents showed that capillary suction time (CST) increased linearly from 34.90 ± 0.10 s to 104.90 ± 0.30 s (R2 = 0.92, p < 0.01), whereas the solid content of centrifuge cake decreased from 21.23 %±0.45 % to 12.52 %±0.14 % (R2 = 0.89, p < 0.01) when organic fractionincreased from 35.72 % to 61.11 %. These results first confirmed that WAS dewatering performance was negatively correlated to its organic content. Then, the underlying mechanism was revealed by studying the basic physicochemical properties of WAS with various organic content. The results showed that sludge with a higher organic content generally had greater extracellular polymeric substances (EPS) content, lower density and higher negative zeta potential, which hinder the aggregation and flocculation of floc particles. These properties endow the WAS with a higher organic content generally possessed more bound water content, small pores, poorer fluidity, and stronger network strength. These characteristics can hamper the separation of water from sludge cake during dewatering. Based on which, this study discussed the potential of organic fraction as a surrogate of EPS for evaluating WAS dewaterability and indicated the organic fraction can be a useful and strong indicator of WAS dewaterability.
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Affiliation(s)
- Hou-Feng Wang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; CAS Key Laboratory for Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Hao Hu
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China; School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, Anhui 230022, China
| | - Hua-Jie Wang
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China; School of Environmental and Chemical Engineering, Anhui Vocational and Technical College,Hefei, Anhui 230011, China
| | - Ya-Nan Bai
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Xiao-Fei Shen
- College of Environmental Science and Technology, Anhui Normal University, Wuhu, Anhui 241000,China
| | - Wei Zhang
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Raymond Jianxiong Zeng
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China; CAS Key Laboratory for Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China.
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31
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Tang SM, Xu ZH, Liu YL, Yang GF, Mu J, Jin RC, Yang Q, Zhang XL. Performance, kinetics characteristics and enhancement mechanisms in anammox process under Fe(II) enhanced conditions. Biodegradation 2020; 31:223-234. [DOI: 10.1007/s10532-020-09905-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 06/04/2020] [Indexed: 02/05/2023]
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32
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Fan X, Wang Y, Zhang D, Guo Y, Gao S, Li E, Zheng H. Effects of acid, acid-ZVI/PMS, Fe(II)/PMS and ZVI/PMS conditioning on the wastewater activated sludge (WAS) dewaterability and extracellular polymeric substances (EPS). J Environ Sci (China) 2020; 91:73-84. [PMID: 32172984 DOI: 10.1016/j.jes.2020.01.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/10/2020] [Accepted: 01/12/2020] [Indexed: 06/10/2023]
Abstract
The effects of four conditioning approaches: Acid, Acid-zero-valent iron (ZVI)/peroxydisulfate (PMS), Fe(II)/PMS and ZVI/PMS, on wastewater activated sludge (WAS) dewatering and organics distribution in supernatant and extracellular polymeric substances (EPS) layers were investigated. The highest reduction in bound water and the most WAS destruction was achieved by Acid-ZVI/PMS, and the optimum conditions were pH 3, ZVI dosage 0.15 g/g dry solid (DS), oxone dosage 0.07 g/g DS and reaction time 10.6 min with the reductions in capillary suction time (CST) and water content (Wc) as 19.67% and 8.49%, respectively. Four conditioning approaches could result in TOC increase in EPS layers and supernatant, and protein (PN) content in tightly bound EPS (TB-EPS). After conditioning, organics in EPS layers could migrate to supernatant. Polysaccharide (PS) was easier to migrate to supernatant than PN. In addition, Acid, Acid-ZVI/PMS or Fe(II)/PMS conditioning promoted the release of some polysaccharides containing ring vibrations v PO, v C-O-C, v C-O-P functional groups from TB-EPS. ESR spectra proved that both radicals of SO4-· and ·OH contributed to dewatering and organics transformation and migration. CST value of WAS positively correlated with the ratios of PN/PS in LB-EPS and total EPS, while it negatively correlated with TOC, PN content and PS content in TB-EPS, as well as PS content in supernatant and LB-EPS. BWC negatively correlated to zeta potential and TOC value, PN content, and HA content in supernatant.
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Affiliation(s)
- Xiaoyang Fan
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Yili Wang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China; Jinyun Forest Ecosystem Research Station, Beijing Forestry University, Beijing 100083, China.
| | - Daxin Zhang
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Yajie Guo
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Shihui Gao
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Enrui Li
- College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China
| | - Huaili Zheng
- Key Laboratory of the Three Gorges Reservoir Regions Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, China
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Guo J, Zhou Y. Transformation of heavy metals and dewaterability of waste activated sludge during the conditioning by Fe 2+-activated peroxymonosulfate oxidation combined with rice straw biochar as skeleton builder. CHEMOSPHERE 2020; 238:124628. [PMID: 31524606 DOI: 10.1016/j.chemosphere.2019.124628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/12/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
This work investigated the improvement performances and mechanisms of waste activated sludge (WAS) dewaterability and the transformation behavior of heavy metals (HMs, including Cu, Zn, Pb, Cd and Cr) by jointly conditioning of Fe2+-activated peroxymonosulfate (PMS) oxidation and rice straw biochar (RS-BC). Experimental results showed that at original WAS pH of 6.5, the joint conditioning was the most effective when PMS dosage was 0.6 mmol·(g-volatile solids (VS))-1, Fe2+/PMS molar ratio was 0.6 and RS-BC dosage was 120 mg·(g-VS)-1. Under this condition, the lowest moisture content (MC) was 38.5% and the standardized-capillary suction time (SCST) was as high as 8.74. For the improvement mechanism, Fe2+-activated PMS oxidation can significantly disintegrate the extracellular polymeric substances (EPS) composing WAS to release EPS-bound water, and the RS-BC was helpful to form porous structures to improve WAS compressibility, facilitating the subsequent dewatering. In addition, Fe2+-activated PMS oxidation can obviously improve the solubilization and reduce the leaching toxicity of Cu, Zn, Pb, Cd and Cr, which was further enhanced by RS-BC. Therefore, the joint application of Fe2+-activated PMS oxidation and RS-BC can be a feasible way to improve WAS dewaterability and reduce HMs risk during WAS dewatering.
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Affiliation(s)
- Junyuan Guo
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China.
| | - Yuling Zhou
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
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Bao H, Yang H, Zhang H, Liu Y, Su H, Shen M. Improving methane productivity of waste activated sludge by ultrasound and alkali pretreatment in microbial electrolysis cell and anaerobic digestion coupled system. ENVIRONMENTAL RESEARCH 2020; 180:108863. [PMID: 31699403 DOI: 10.1016/j.envres.2019.108863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/23/2019] [Accepted: 10/25/2019] [Indexed: 06/10/2023]
Abstract
In order to enhance the productivity of methane from the waste activated sludge (WAS), a coupled system of microbial electrolysis cell (MEC) and anaerobic digestion (AD) was proposed. In this study, alkali, ultrasound-alkali, high-temperature coupled microaeration (TM) were applied as pretreatment methods to disintegrate the WAS flocs and break bacterial cell. After ultrasound-alkali pretreatment, the maximum accumulated concentration of VFAs and SCOD increased by 6.4 and 13.8 times compared with the initial concentration, which were 2.8 and 2.6 times of alkali pretreatment, and 2.1 and 2.1 times of TM pretreatment. Then, the pretreated sludge was transferred into MEC-AD coupled reactors and control group of AD reactors. The results showed that, methane production rate was enhanced to 0.15 m3 CH4/m3 reactor/d in the coupled reactors, which was improved by 3 times compared with control AD (0.05 m3 CH4/m3 reactor/d). The methane yield of MEC-AD coupled reactors achieved 808 ± 8 mL, which were increased by 97.0% ± 1.85% compared to control AD (410 mL). Using MEC can promote the rate of organics degradation and methane yield. The MEC-AD coupled system realized a good performance on the treatment of WAS and improved the efficiency of methane production.
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Affiliation(s)
- Hongxu Bao
- School of Environmental Science, Liaoning University, Shenyang, 110036, China; State Key Laboratory of Urban Water Resources and Environments, Harbin Institute of Technology, Harbin, 150090, China.
| | - Hua Yang
- School of Environmental Science, Liaoning University, Shenyang, 110036, China
| | - Hao Zhang
- School of Environmental Science, Liaoning University, Shenyang, 110036, China
| | - Yichen Liu
- School of Environmental Science, Liaoning University, Shenyang, 110036, China
| | - Hongzhi Su
- School of Environmental Science, Liaoning University, Shenyang, 110036, China
| | - Manli Shen
- School of Environmental Science, Liaoning University, Shenyang, 110036, China
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35
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Faye MCAS, Zhang KK, Peng S, Zhang Y. Sludge dewaterability: The variation of extracellular polymeric substances during sludge conditioning with two natural organic conditioners. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 251:109559. [PMID: 31550604 DOI: 10.1016/j.jenvman.2019.109559] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 08/17/2019] [Accepted: 09/07/2019] [Indexed: 06/10/2023]
Abstract
To assess the characteristics of Extracellular Polymeric Substances during natural organic conditioners for sludge treatment, Moringa oleifera (MO) and chitosan (CTS) were used as conditioners. The findings of this study show that despite the high EPS content due to the fact that this component is not destroyed upon conditioning, sludge conditioned with MO and CTS displayed efficient and improved dewaterability. MO and CTS showed the same mechanism of action by protonation of the negatively charged EPS and reduction of electrostatic repulsions between sludge flocs, thus enhancing sludge filterability by neutralizing and settling. The effect of MO and CTS on EPS lies in their ability to neutralize EPS, settling them. MO and CTS neutralize and aggregate the EPS, hence improving sludge dewaterability. The results indicate that CTS can impact the EPS quantity and quality while MO impacts the EPS quality. Understanding the impact of MO and CTS on sludge EPS can help elucidate the mechanism of their dewaterability efficiency.
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Affiliation(s)
- Marie Christine Amie Sene Faye
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, PR China; Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
| | - Kai Kai Zhang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, PR China; Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
| | - Sun Peng
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, PR China; Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
| | - Yanrong Zhang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, PR China; Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
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Wang BB, Shi X, Liu XT, Zou JT, Li HJ, Peng DC, He F. Insight into the fenton-induced degradation process of extracellular polymeric substances (EPS) extracted from activated sludge. CHEMOSPHERE 2019; 234:318-327. [PMID: 31228834 DOI: 10.1016/j.chemosphere.2019.06.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/22/2019] [Accepted: 06/11/2019] [Indexed: 06/09/2023]
Abstract
Although EPS in microbial aggregates are importance in successful implementation of biological wastewater treatment systems, they also exhibit detrimental role on certain circumstance, such as excess sludge dewatering. Extensive efforts have been put into the disruption of EPS for improving the dewaterability of excess sludge and Fenton's reagent treatment has been demonstrated to be a very promising sludge conditioning method for EPS destruction. However, the information regarding detailed degradation process of EPS during Fenton's reagent treatment is limited. In this study, EPS were extracted from activated sludge and treated with different concentrations of Fenton's reagent. The physicochemical characteristic changes of EPS under different treatment were investigated in terms of components, EEM, molecular weight (MW), UV-Vis and FTIR. The results showed that EPS were prone to be disintegrated, but hard to be fully mineralized. Humic substances in EPS were more resistant to Fenton's reagent than other components. Low MW components of EPS were preferentially degraded prior to the disruption of high MW components. Besides, the disintegration of EPS into lower MW ones was accompanied by the formation of higher MW compounds caused by the bridge interaction of Fe ions. The cleavage of protein's backbone in EPS was mainly through destruction of amide II (N-H and C-N) in -CO-NH-. Fenton's reagent treatment also led to a significant increase of oxygen-containing functional groups in EPS molecules. This paper may pave a path to deeply understand the mechanisms of dewatering improvements of excess sludge by Fenton's conditioning.
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Affiliation(s)
- Bin-Bin Wang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Xiang Shi
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Xue-Ting Liu
- Hangzhou Tianchuang Environmental Technology Co., Ltd, Hangzhou, 311121, China
| | - Jin-Te Zou
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Hui-Juan Li
- School of Environmental and Chemical Engineering, Xi'an Polytechnic University, Xi'an, Shaanxi, 710048, China
| | - Dang-Cong Peng
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, 710055, China
| | - Feng He
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China.
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37
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He ZW, Tang CC, Liu WZ, Ren YX, Guo ZC, Zhou AJ, Wang L, Yang CX, Wang AJ. Enhanced short-chain fatty acids production from waste activated sludge with alkaline followed by potassium ferrate treatment. BIORESOURCE TECHNOLOGY 2019; 289:121642. [PMID: 31226670 DOI: 10.1016/j.biortech.2019.121642] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
This study reported an efficient approach, i.e., alkaline followed by potassium ferrate (PF) pretreatment, to enhance short chain fatty acids (SCFAs) production from waste activated sludge anaerobic fermentation process. The optimum condition was initial pH of 10.0 and PF dosage of 28 mg Fe(VI)/g total suspended solid, with the highest SCFAs production of 382 mg chemical oxygen demand/g volatile suspended solid, which was 2.03 and 2.06 times higher than that of corresponding sole treatments. It was found that the alkaline + PF treatment could provide more soluble substrates for subsequent acidification process by accelerating disruption of both microbial cells and extracellular polymeric substances. And the alkaline + PF treatment also benefited to the activity promotion of specific hydrolases and inhibition of methanogens. Besides, the abundances of microorganisms related to SCFAs production, such as Proteiniclasticum and Macellibacteroides, were increased greatly, whereas the main SCFAs consumer, Proteobacteria, was decreased from 29.1% to 14.4%.
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Affiliation(s)
- Zhang-Wei He
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Cong-Cong Tang
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Wen-Zong Liu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China.
| | - Yong-Xiang Ren
- Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Ze-Chong Guo
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212005, China
| | - Ai-Juan Zhou
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Ling Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Chun-Xue Yang
- School of Geography and Tourism, Harbin University, Harbin 150086, China
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China
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38
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Olvera-Vargas H, Zheng X, Garcia-Rodriguez O, Lefebvre O. Sequential "electrochemical peroxidation - Electro-Fenton" process for anaerobic sludge treatment. WATER RESEARCH 2019; 154:277-286. [PMID: 30802702 DOI: 10.1016/j.watres.2019.01.063] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/21/2019] [Accepted: 01/30/2019] [Indexed: 05/03/2023]
Abstract
In this study, we present a sequential electrochemical process for integral treatment of anaerobic sludge, combining for the first time electrochemical peroxidation (ECP) and electro-Fenton (EF). In the first step, ECP (consisting of H2O2-assisted electrocoagulation with Fe electrodes) was applied as a conditioning and stabilizing method, whose synergistic electrocoagulation/Fenton oxidation effects considerably reduced the COD, TOC and total suspended solids (TSS) by 89.3%, 75.4% and 85.6%, respectively, under optimized conditions (initial pH of 5, [H2O2]/[Fe2+] dose ratio of 5, 15.38 mA cm-2 and 2 h treatment). Furthermore, total coliforms were completely killed within the first hour of treatment. In the second step, EF was successfully applied to mineralize the remaining organic fraction in the liquid effluent after dewatering, achieving 91.6% and 87.2% of COD and TOC removal, respectively, after 4 h of treatment under optimal conditions (pH 3 and 25 mA cm-2), while almost total COD and TOC removal was attained in 8 h. The Fe sludge generated at the end of the ECP treatment was easily dewatered by filtration and 20.9 g of nutrient-rich dry sludge were produced. The overall cost of the ECP-EF treatment was S$ 0.05 L-1 sludge. The combined effects of coagulation and Fenton oxidation during ECP revealed that the treatment efficiency is strongly dependent on the rheological properties of the sludge sample.
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Affiliation(s)
- H Olvera-Vargas
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576, Singapore
| | - X Zheng
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576, Singapore
| | - O Garcia-Rodriguez
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576, Singapore
| | - O Lefebvre
- Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore, 117576, Singapore.
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39
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Li H, Song L, Han B, Song H, Bai R, Li H, Wang Q, Lin Z, Hu W. Highly efficient enhancement of municipal sludge dewaterability using persulfate activation with nZVI/HA. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 79:1309-1315. [PMID: 31123230 DOI: 10.2166/wst.2019.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This study presents a sulfate radical-based oxidation method for improving municipal sludge dewaterability by combining persulfate and nanoscale zero-valent iron supported on humic acid (nZVI/HA-PS). Sludge dewaterability using persulfate activation with nZVI/HA was assessed for specific resistance to filterability (SRF), time to filter (TTF), settling volume percentage (SV30) and water content (Wc). The influencing factors, such as mass ratios of nZVI to HA, initial pH, PS dosage and nZVI/HA nanocomposite dosage, were investigated. Experimental results indicated that the SRF reduction efficiency of the sludge reached 86.47% using initial concentrations of 1.2 mmol/gVSS PS and 300 mg/L nZVI/HA. The soluble chemical oxygen demand (SCOD) of sludge supernatants increased from 79 mg/L to 710 mg/L under optimum conditioning, indicating that sludge flocs were effectively decomposed. Economic analysis demonstrated that the nZVI/HA-PS conditioning process is a potential method for improving sludge dewaterability.
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Affiliation(s)
- Hao Li
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Lei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Baohong Han
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Hongwei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Runying Bai
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Huidong Li
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Qian Wang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Zhipeng Lin
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
| | - Wenbin Hu
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, China E-mail:
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40
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Jin B, Niu J, Dai J, Li N, Zhou P, Niu J, Zhang J, Tao H, Ma Z, Zhang Z. New insights into the enhancement of biochemical degradation potential from waste activated sludge with low organic content by Potassium Monopersulfate treatment. BIORESOURCE TECHNOLOGY 2018; 265:8-16. [PMID: 29864736 DOI: 10.1016/j.biortech.2018.05.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 06/08/2023]
Abstract
Waste activated sludge with low organic content (WAS-LOC) always led to the failure of anaerobic fermentation. A potentially practical technology based on SO4-, i.e. Potassium Monopersulfate (PMS) was used into WAS-LOC anaerobic fermentation system and had been presented to greatly improve both the intracellular and extracellular constituents, which improved the biological enzyme activity and produced a mass of short-chain fatty acids (SCFAs). Results showed that the maximal SCFAs production was 716.72 mg chemical oxygen demand (COD)/L (0.08 mg PMS/mg SS), which increased to 43.70 times comparing to that of 0.00 mg PMS/mg SS level (16.40 mgCOD/L). The activities of biological enzymes increased 1.42 times for protease, 4.38 times for α-glucosidase, 2.1 times for alkaline phosphatase, 1.70 times for acidic phosphatase and 1.37 times for dehydrogenase respectively comparing to natural fermentation system, but the coenzyme 420 was restrained prominently. PMS positively enriched the abundance of microbial community responsible for WAS-LOC hydrolysis and SCFAs production.
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Affiliation(s)
- Baodan Jin
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China.
| | - Jintao Niu
- HE NAN GENGAN HUANBAO KEJIYOUXIANGONGSI, Zhengzhou 450001, China
| | - Jingwen Dai
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Nuonan Li
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Ping Zhou
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Jiahui Niu
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Ju Zhang
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Hongfan Tao
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Zhigang Ma
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
| | - Zhongfang Zhang
- Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450001, China
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41
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Bian B, Zhang L, Zhang Q, Zhang S, Yang Z, Yang W. Coupled heating/acidification pretreatment of chemical sludge for dewatering by using waste sulfuric acid at low temperature. CHEMOSPHERE 2018; 205:260-266. [PMID: 29702345 DOI: 10.1016/j.chemosphere.2018.04.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 04/07/2018] [Accepted: 04/20/2018] [Indexed: 06/08/2023]
Abstract
A cost-effective approach for pretreatment of chemical sludge for further dewatering, based on the idea of "using waste to treat waste", is provided. It is a coupled heating/acidification pretreatment method, where waste sulfuric acid is employed and relatively low temperatures (<100 °C) are applied. Effects of reaction time, temperature, and dosage of waste acid on dewatering performance (both dewatering speed and degree) are studied. Under the optimal conditions (reaction time: 30 min; temperature: 90 °C; waste acid dosage: 0.175 g/(g dried sludge)), the method of this work demonstrates three advantages compared to the conventional method using lime+polyacrylamide: lower moisture content of treated sludge; higher calorific value for incineration process; and lower cost. Detailed mechanism of the pretreatment for dewatering is investigated via characterizations and statistical analyses of various parameters, among which zeta potential, particle size, protein and polysaccharide contents, soluble chemical oxygen demand (SCOD), reduction of combined water and volatile suspended solid (VSS), are associated with dewatering performance. Both heating and acidification generate disintegration of cells in sludge, giving rise to two phenomena: more organic matters are released into solution and more bound water turns into free water. Meantime, the released organic polymers flocculate sludge particles, further accelerating the solid-liquid separation process.
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Affiliation(s)
- Bo Bian
- School of Environment, School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Limin Zhang
- School of Environment, School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China.
| | - Qin Zhang
- College of Environment, Hohai University, Nanjing 210098, PR China
| | - Shaopeng Zhang
- School of Environment, School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China
| | - Zhen Yang
- School of Environment, School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China.
| | - Weiben Yang
- School of Environment, School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China.
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42
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Wang BB, Liu XT, Chen JM, Peng DC, He F. Composition and functional group characterization of extracellular polymeric substances (EPS) in activated sludge: the impacts of polymerization degree of proteinaceous substrates. WATER RESEARCH 2018; 129:133-142. [PMID: 29145083 DOI: 10.1016/j.watres.2017.11.008] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/28/2017] [Accepted: 11/02/2017] [Indexed: 05/16/2023]
Abstract
Characteristics of extracellular polymeric substances (EPS) in activated sludge strongly depend on wastewater substrates. Proteinaceous substrates (ProS) present in heterogeneous polymeric form are intrinsic and important parts of wastewater substrates for microorganisms in activated sludge systems. However, correlations between ProS and characteristics of EPS are scarce. This study systematically explored the impacts of monomeric (Mono-), low polymeric (LoP-) and high polymeric (HiP-) ProS on compositions and functional groups of EPS in activated sludge. The results showed that the change of polymerization degree of ProS significantly altered the composition of EPS. Compared to EPSMono-ProS, the proportion of proteins in EPSLoP-ProS and EPSHiP-ProS increased by 12.8% and 27.7%, respectively, while that of polysaccharides decreased by 22.9% and 63.6%, respectively. Moreover, the proportion of humic compounds in EPSLoP-ProS and EPSHiP-ProS were ∼6 and ∼16-fold higher than that in EPSMono-ProS, respectively. The accumulation of humic compounds in EPS increased the unsaturation degree of EPS molecules, and thereby reduced the energy requirement for electrons transition of amide bonds and aromatic groups. Size exclusion chromatography (SEC) analyses detected more molecular clusters in EPSHiP-ProS, indicating more complex composition of EPS in HiP-ProS fed activated sludge. Spectroscopic characterization revealed the dominance of hydrocarbon, protein, polysaccharide and aromatic associated bonds in all three EPS. Nevertheless, with the increase of polymerization degree of ProS, the protein associated bonds (such as CONH, CO, NC, NH) increased, while the polysaccharide associated bonds (such as COC, COH, OCOH) decreased. This paper paves a path to understand the role of ProS in affecting the production and characteristics of EPS in biological wastewater treatment systems.
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Affiliation(s)
- Bin-Bin Wang
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Hangzhou, Zhejiang, 310014, China
| | - Xue-Ting Liu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Jian-Meng Chen
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Hangzhou, Zhejiang, 310014, China
| | - Dang-Cong Peng
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, 710055, China
| | - Feng He
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Hangzhou, Zhejiang, 310014, China.
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43
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He ZW, Liu WZ, Gao Q, Tang CC, Wang L, Guo ZC, Zhou AJ, Wang AJ. Potassium ferrate addition as an alternative pre-treatment to enhance short-chain fatty acids production from waste activated sludge. BIORESOURCE TECHNOLOGY 2018; 247:174-181. [PMID: 28950124 DOI: 10.1016/j.biortech.2017.09.073] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/07/2017] [Accepted: 09/09/2017] [Indexed: 05/16/2023]
Abstract
A potentially practical technology based on ferrate (VI), i.e. potassium ferrate (PF), pretreatment integrated into waste activated sludge (WAS) anaerobic fermentation has been presented to greatly enhance short-chain fatty acids (SCFAs) production with a shortened fermentation time. The maximum production of SCFAs, 343mg chemical oxygen demand/g volatile suspended solid with acetic acid proportion of 48.2%, was obtained with PF dosage of 56mg Fe(VI)/g total suspended solid within 5days, which was increased to 5.72times compared to that of control. The mechanism study showed that PF accelerated the release rate of both intracellular and extracellular constituents. And the activities of key hydrolytic enzymes were much improved with PF addition. Moreover, PF positively enriched the abundance of microorganisms responsible for WAS hydrolysis and SCFAs production, especially acetic acid-forming characteristic genera such as Petrimonas, Fusibacter and Acetoanaerobium. Besides, the incubation time of acidogenesis and methanogenesis were separated by PF.
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Affiliation(s)
- Zhang-Wei He
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wen-Zong Liu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Qin Gao
- Daqing Refining & Chemical Company, Daqing 163411, Heilongjiang, China
| | - Cong-Cong Tang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ling Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ze-Chong Guo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ai-Juan Zhou
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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44
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Zhou X, Jin W, Chen H, Chen C, Han S, Tu R, Wei W, Gao SH, Xie GJ, Wang Q. Enhancing dewaterability of waste activated sludge by combined oxidative conditioning process with zero-valent iron and peroxymonosulfate. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:2427-2433. [PMID: 29144300 DOI: 10.2166/wst.2017.408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The enhancement of sludge dewaterability is of great importance for facilitating the sludge disposal during the operation of wastewater treatment plants. In this study, a novel oxidative conditioning approach was applied to enhance the dewaterability of waste activated sludge by the combination of zero-valent iron (ZVI) and peroxymonosulfate (PMS). It was found that the dewaterability of sludge was significantly improved after the addition of ZVI (0-4 g/g TSS) (TSS: total suspended solids) and PMS (0-1 g/g TSS). The optimal addition amount of ZVI and PMS was 0.25 g/g TSS and 0.1 g/g TSS, respectively, under which the capillary suction time of the sludge was reduced by approximately 50%. The decomposition of sludge flocs could contribute to the improved sludge dewaterability. Economic analysis demonstrated that the proposed conditioning process with ZVI and PMS was more economical than the ZVI + peroxydisulfate and the traditional Fenton conditioning processes.
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Affiliation(s)
- Xu Zhou
- Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China
| | - Wenbiao Jin
- Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China
| | - Hongyi Chen
- Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, Harbin 150001, China
| | - Songfang Han
- Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China
| | - Renjie Tu
- Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China
| | - Wei Wei
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, Harbin 150001, China
| | - Shu-Hong Gao
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Guo-Jun Xie
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, Harbin 150001, China
| | - Qilin Wang
- Griffith School of Engineering, Griffith University, Nathan Campus, Brisbane, QLD 4111, Australia and Centre for Clean Environment and Energy, Griffith University, Gold Coast Campus, Gold Coast, QLD 4222, Australia E-mail:
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45
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Wu B, Ni BJ, Horvat K, Song L, Chai X, Dai X, Mahajan D. Occurrence State and Molecular Structure Analysis of Extracellular Proteins with Implications on the Dewaterability of Waste-Activated Sludge. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9235-9243. [PMID: 28741346 DOI: 10.1021/acs.est.7b02861] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The occurrence state and molecular structure of extracellular proteins were analyzed to reveal the influencing factors on the water-holding capacities of protein-like substances in waste-activated sludge (WAS). The gelation process of extracellular proteins verified that advanced oxidation processes (AOPs) for WAS dewaterability improvement eliminated the water affinity of extracellular proteins and prevented these macromolecules from forming stable colloidal aggregates. Isobaric tags for relative and absolute quantitation proteomics identified that most of the extracellular proteins were originally derived from the intracellular part and the proteins originally located in the extracellular part were mainly membrane-associated. The main mechanism of extracellular protein transformation during AOPs could be represented by the damage of the membrane or related external encapsulating structure and the release of intracellular substances. For the selected representative extracellular proteins, the strong correlation (R2 > 0.97, p < 0.03) between the surface hydrophilicity index and α-helix percentages in the secondary structure indicated that the water affinity relied more on the spatial distribution of hydrophilic functional groups rather than the content. Destructing the secondary structure represented by the α-helix and stretching the polypeptide aggregation in the water phase through disulfide bond removal might be the key to eliminating the inhibitory effects of extracellular proteins on the interstitial water removal from WAS.
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Affiliation(s)
- Boran Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University , 1239 Siping Road, Shanghai 200092, China
| | - Bing-Jie Ni
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University , 1239 Siping Road, Shanghai 200092, China
| | - Kristine Horvat
- College of Engineering and Applied Science, Stony Brook University , 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Liyan Song
- Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science (CAS) , 266 Fangzheng Avenue, Chongqing 400714, China
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University , 1239 Siping Road, Shanghai 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University , 1239 Siping Road, Shanghai 200092, China
| | - Devinder Mahajan
- College of Engineering and Applied Science, Stony Brook University , 100 Nicolls Road, Stony Brook, New York 11794, United States
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Liu C, Wu B, Chen X, Xie S. Waste activated sludge pretreatment by Fe(II)-activated peroxymonosulfate oxidation under mild temperature. CHEMICAL PAPERS 2017. [DOI: 10.1007/s11696-017-0228-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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47
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Nitrite addition to acidified sludge significantly improves digestibility, toxic metal removal, dewaterability and pathogen reduction. Sci Rep 2016; 6:39795. [PMID: 28004811 PMCID: PMC5177897 DOI: 10.1038/srep39795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 11/29/2016] [Indexed: 11/08/2022] Open
Abstract
Sludge management is a major issue for water utilities globally. Poor digestibility and dewaterability are the main factors determining the cost for sludge management, whereas pathogen and toxic metal concentrations limit beneficial reuse. In this study, the effects of low level nitrite addition to acidified sludge to simultaneously enhance digestibility, toxic metal removal, dewaterability and pathogen reduction were investigated. Waste activated sludge (WAS) from a full-scale waste water treatment plant was treated at pH 2 with 10 mg NO2--N/L for 5 h. Biochemical methane potential tests showed an increase in the methane production of 28%, corresponding to an improvement from 247 ± 8 L CH4/kg VS to 317 ± 1 L CH4/kg VS. The enhanced removal of toxic metals further increased the methane production by another 18% to 360 ± 6 L CH4/kg VS (a total increase of 46%). The solids content of dewatered sludge increased from 14.6 ± 1.4% in the control to 18.2 ± 0.8%. A 4-log reduction for both total coliforms and E. coli was achieved. Overall, this study highlights the potential of acidification with low level nitrite addition as an effective and simple method achieving multiple improvements in terms of sludge management.
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Zheng Y, Ke L, Xia D, Zheng Y, Wang Y, Li H, Li Q. Enhancement of digestates dewaterability by CTAB combined with CFA pretreatment. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2016.01.052] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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49
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Liu J, Wei Y, Li K, Tong J, Wang Y, Jia R. Microwave-acid pretreatment: A potential process for enhancing sludge dewaterability. WATER RESEARCH 2016; 90:225-234. [PMID: 26734782 DOI: 10.1016/j.watres.2015.12.012] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/10/2015] [Accepted: 12/09/2015] [Indexed: 05/16/2023]
Abstract
Activated sludge is hard to be dewatered due to the highly water bounded in sludge flocs. This study investigated the hybrid treatment of microwave irradiation and acidification on sludge dewaterability as well as its mechanism. Results showed that the combined microwave-acid treatment (T = 100 °C, initial pH = 2.5) was effective for improving sludge dewaterability, e.g. capillary suction time (CST) decreased from 37.7 s to 9.2 s, bound water content decreased from 1.96 ± 0.19 g/g Dry Sludge (DS) to 0.88 ± 0.24 g/g DS. The treated sludge showed more fluidity and less thixotropy. Both MW heating temperature and pH played important roles in improving sludge dewaterability. Higher temperature was beneficial for sludge disintegration, but the released polymers resulted in highly negative zeta potential and deteriorated sludge dewaterability. The acidification was capable of reducing the negative zeta potential, increasing flocs size and finally improving sludge dewaterability. According to the analysis of molecule weight distribution and 3D-EEM, the fractions of polymers especially protein-like substances at molecule weight of 10(4)-10(5) Da were the key organics related to sludge dewaterability, but not the humic acid-like and fulvic acid-like substances.
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Affiliation(s)
- Jibao Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
| | - Yuansong Wei
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; Institute of Energy, Jiangxi Academy of Sciences, Nanchang, 330096, PR China.
| | - Kun Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
| | - Juan Tong
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
| | - Yawei Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
| | - Ruilai Jia
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China
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50
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Ahmad M, Abdul Raman AA, Basirun WJ, Bhargava SK. Treatment of textile effluent containing recalcitrant dyes using MOF derived Fe-ZSM-5 heterogeneous catalyst. RSC Adv 2016. [DOI: 10.1039/c6ra01687a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fe-ZSM-5 is synthesized through a newly established 2-step process. 82% yield of Fe-ZSM-5 catalyst is possible at low temperature and pressure. 100% degradation of dyes is achieved with lesser amounts of catalyst and H2O2.
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Affiliation(s)
- Mushtaq Ahmad
- Department of Chemical Engineering
- Faculty of Engineering
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Abdul Aziz Abdul Raman
- Department of Chemical Engineering
- Faculty of Engineering
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Wan Jefrey Basirun
- Department of Chemistry
- Faculty of Science
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Suresh K. Bhargava
- Advanced Materials and Industrial Chemistry Group
- School of Applied Sciences
- RMIT University
- Melbourne-3001
- Australia
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